Technical Field
The present disclosure relates to an epitaxial structures and an epitaxial growth method for forming an epitaxial layer with cavities.
Description of Related Art
There has been rapid progress in technologies of light emitting diodes (LEDs) in recent years. For the purpose of increasing the light-extraction ratio of LEDs, techniques such as patterned sapphire substrates have been widely applied in LEDs, which include gallium nitride. For further increasing the light-extraction ratio, it have been purposed to form cavities or pores in epitaxial gallium nitride layers of LEDs. In this regard, it is difficult to well control the shape and the volume of the cavities in LEDs, and therefore the quality of LEDs is unstable in prior art. In view of the above, there exists a need of a new method that would improve the drawbacks in prior art.